The Israel Defense Forces (IDF) announced the discovery of the tunnels and began destroying them on Monday night.

The IDF said that the tunnels were not complete and did not pose an immediate threat, but that they did stretch into Israeli territory.

Several areas close to the northern security fence have been declared closed military zones and there is an increased IDF presence there, the IDF said in a statement. The statement added that there currently are no special instructions for residents of the north and that they should go about their normal routine, though farmers reportedly were warned to stay away from the border.

The military is destroying the tunnels from Israel’s side of the border.

“We are in complete control of the operation, and we are determined to remove the threat of the tunnels from Israel’s northern border,” IDF spokesperson Ronen Manelis said in a statement. “The Hezbollah terror organization, which is behind the digging of the tunnels, continues to operate with Iranian support and funding in order to establish its terrorist activity against Israeli citizens.”

Manelis told Israeli media that the IDF has been planning for this operation “for a very long time.”

Hamas in Gaza reportedly provided Hezbollah with information on how to build such tunnels, after building several between the coastal strip and southern Israel.

The IDF had been aware since 2013 of Hezbollah plans to build the tunnels. It took at least two years to create tunnel-locating technology. Residents living on Israel’s northern border have in recent years reported hearing sounds of digging going on underground.

Hezbollah on Friday posted a threatening video showing satellite images and map locations of strategic sites in Israel, accompanied by the message: “Attack and you will regret it.” The video was posted hours after an alleged Israeli airstrike on Iranian and Hezbollah targets in Syria.